In a surface emitting laser element, laser oscillation is generally caused by oscillating light between two light reflection layers (distributed Bragg reflector layers, DBR layers). Accordingly, it is necessary to smooth a semiconductor surface for forming a DBR layer in sub-nanometer order. When an appropriate smoothness cannot be obtained, optical reflectance of each DBR layer is lowered, and variations in the characteristics (oscillation threshold and the like) are increased, which eventually makes it difficult to even obtain laser oscillation.
A method of manufacturing a nitride surface emitting laser using a selective growth method is known from Japanese Patent Application Laid-Open No. 10-308558. That is, a method of manufacturing a nitride semiconductor laser element disclosed in the laid-open patent application includes
a step of selectively forming a multilayer film made of dielectric on a substrate surface,
a step of growing a nitride semiconductor layer on top of the multilayer film,
a step of growing a nitride semiconductor layer including an active layer on top of the nitride semiconductor layer formed on top of the multilayer film, and
a step of using the multilayer film as at least one reflecting mirror for light emission of the active layer.